Three studies of aging and spatial cognition are outlined in this proposal. Specifically, these studies are concerned with perceptual differentiation/selection and temporospatial integration, both of which are posited to be important processes in the acquisition and use of spatial knowledge of large-scale environments. Experiments 1 and 2 are designed to (a) compare the performance of elderly adults to that of young adults on tasks requiring these two processes and (b) explore the relationships between these processes and other cognitive abilities as measured by psychometric-based instruments. Experiment 3 deals with the relationship between performance on laboratory tasks involving perceptual differentiation/selection and temporospatial integration and performance on a series of macrospatial tasks in a real-world environment. Findings of the studies should be relevant to theoretical issues in aging and cognition as well as to practical issues concerning mobility and quality of life for elderly adults.